No idea where to post this. Need information on how to pay past due Gamepass balance.

I apologize since this is more than likely going to be in the wrong section. TBH, it took me entirely too long to even find somewhere even remotely close to where this should go. Anyway...

I used up all of my rewards points in order to get a gift card to pay the past due balance. As you can see in the pictures, I should have more than enough to cover it yet there is absolutely nowhere to use the funds to pay it off? I'm...probably missing something simple...or insanely convoluted, neither would surprise me!

Thanks for reading! And again, apologies if this is ...wrong place.